Machine for establishing a controlled atmosphere in packages

ABSTRACT

Filled but unsealed pouches are automatically loaded into holders which then are lowered into chambers in a turret for step-by-step indexing through vacuum and gas stations where virtually all of the oxygen is removed from the pouches. Thereafter, the pouches are sealed in the presence of a nonoxidizing gas and then are indexed and raised upwardly out of the chambers preparatory to being automatically unloaded from the holders.

United States Patent [191 7 Canfield Oct. 7, 1975 MACHINE FORESTABLISHING A 3,488,915 1/1970 Delestatius 53/112 A CONTROLLEDATMOSPHERE IN 3,508,373 4/1970 Robinson, Jr. 53/1 12 RX PACKAGES AllenB. Canfield, Rockford, Ill.

Assignee: Rexham Corporation, Rockford, Ill.

Filed: Sept. 25,1974

Appl. No.: 508,982

Inventor:

US. Cl 53/112 B; 53/95; 53/373 Int. Cl. B65B 31/02 Field of Search53/86, 89, 95, 96, 110,

53/110 R, 110 A, '1 10 B, 183, 353, 373

References Cited UNITED STATES PATENTS 9/1963 Grafingholt 53/95 11/1965Buchner 53/95 X 12/1969 Rausing et a1 53/112 BX Primary ExaminerRobertL. Spruill Assistant ExaminerLe0n Gilden Attorney, Agent, or Firm-Wolfe,Hubbard, Leydig, Voit & Osann, Ltd.

[5 7 ABSTRACT Filled but unsealed pouches are automatically loaded intoholders which then are lowered into chambers in a turret forstep-by-step indexing through vacuum and gas stations where virtuallyall of the oxygen is removed from the pouches. Thereafter, the pouchesare sealed in the presence of a non-oxidizing gas and then are indexedand raised upwardly out of the chambers preparatory to beingautomatically unloaded from the holders.

15 Claims, 14 Drawing Figures US. Patent (M11975 Sheet 1 of7 3,910,009

atent 0a. 7,1975 Sheet 2 of 7 3,910,009

atem

Get. 7,1975 Shegt 4 of 7 US. Patent 0m. 7,1975 Sheet 6 of7 3,910,009

Sheet 7 0f 7 3,910,009

Oct. 7,1975

US. Patent MACHINE FOR ESTABLISHING A CONTROLLED ATMOSPHERE IN PACKAGESBACKGROUND OF THE INVENTION This invention relates to a machine forestablishing a non-oxidizing atmosphere in newly filled packages and forthereafter closing the open ends of the packages. Machines forperforming these functions are disclosed in Bartelt US. Pat. No.2,649,671; Johnson US. Pat. No. 3,619,975 and Schulze U.S. Pat. No.3,708,952.

SUMMARY OF THE INVENTION The general aim of the present invention is toprovide a new and improved machine which is capable of establishing inthe packages an atmosphere having an extremely low oxygen content, theforegoing being achieved by subjecting the packages to several distinctoxygen purging operations after the packages have been filled and beforethe packages are closed.

A more detailed object is to provide a machine in which the newly filledpackages are purged of oxygen at several stations as the packages areindexed step-bystep by a turret, the packages being carried withinunique chambers in the turret and being both evacuated and filled with anon-oxidizing gas as the chambers are moved to different stations duringindexing of the turret.

Another object of the invention is to provide novel holders which notonly carry the packages in the indexv able chambers but which also loadthe packages into and unload the packages from the chambers.

The invention also resides in the unique and comparatively simpleconstruction of the turret to keep the various chambers in a sealedcondition and to avoid the need for using complex valving between thechambers and the vacuum and gas sources.

These and other objects and advantages of the invention will become moreapparent from the following detailed description when taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective viewschematically showing a new and improved machine incorporating theunique features of the present invention.

FIG. 2 is a plan view of the machine.

FIG. 3 is a fragmentary cross-section taken substantially along the line33 of FIG. 2.

FIG. 4 is a perspective view showing a filled and unsealed package ofthe type which is delivered to and handled by the machine.

FIG. 5 is a perspective view of one of the holders.

FIG. 6 is a plan view of the holder shown in FIG. 5.

FIG. 7 is a fragmentary cross-section taken substantially along the line7-7 of FIG. 6.

FIGS. 8 and 9 are enlarged fragmentary crosssections taken substantiallyalong the lines 88 and 99, respectively, of FIG. 2 FIG. 10 is afragmentary cross-section taken substantially along the line 1010 ofFIG. 3.

FIG. 11 is a fragmentary cross-section taken substantially along theline l1--1l of FIG. 10.

FIGS. 12 and 13 are enlarged fragmentary crosssections takensubstantially along the lines l2l2 and 1313, respectively, of FIG. 2.

package FIG. 14 is a perspective view showing the package after it hasbeen purged and sealed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT As shown in thedrawings for purposes of illustration, the invention is embodied in amachine 15 for establishing a controlled and preferably non-oxidizingatmosphere within newly filled packages which herein are shown beingcomparatively flat pouches 16 (FIG. 4) made of flexible heat sealablematerial. Thepouches are formed and filled on a Bartelt horizontalintermittent motion packager indicated generally by the referencenumeral 17 (FIG. 1), each pouch in this instance being filled withseveral thin slices of meat such as corned beef or turkey. The flavorand quality of the product may be maintained for a longer period of timeif the pouches are purged of oxygen before their upper ends are sealed.

The present invention contemplates a new and improved machine 15 whichreceives the filled but unsealed pouches 16 from the packager l7 andadvances the pouches through several conditioning stations 19 to 24(FIG. 2) where the pouches are periodically evacuated and filled with anon-oxidizing gas to establish an extremely low oxygen level in thepouches. The machine then seals the upper ends of the pouches in thepresence of a non-oxidizing gas and therafter automatically delivers thecompleted pouches to a remote station for further processing. By purgingthe pouches of oxygen with a machine 15 which is separate from the mainpackager 17, a lower oxygen content may be established and particularlywhen the pouches contain a difficuIt-to-fill product such as sliced meatwhich com plicates purging by the methods presently available for use onthe packager itself.

More specifically, the machine 15 includes a turret 25 (FIGS. 1 and 2)which is located near the discharge end of the packager I7 and which isadapted to be indexed step-by-step about an upright axis in timedrelation with the delivery of the newly filled pouches 16 from thepackager. The turret is formed with twelve angularly spaced shells 26(FIG. 3) which define separate upwardly opening chambers 27 each adaptedto be loaded with a pouch. Associated with each chamber is a pouchholder 29 (FIGS. 5 to 7) adapted to move between an extended positionraised out of the chamber and a retracted position located in thechamber (see the two positions shown in FIG. 3). At a loading station 30(FIGS. 2 and 3), a pouch from the packager 17 is delivered automaticallyintoeach holder while the latter is in its extended or raised positionand while the turret 25 is dwelling. Thereafter, the turret is indexedone step to a station 31 (FIGS. 3 and 8) and the holder and the pouchare lowered downwardly into the associated chamber 27.

During subsequent indexing of the turret 25, each newly loaded chamber27 dwells successively at two angularly spaced vacuum stations 19 and 20(FIG. 2). a gas station 21, two additional vacuum stations 22 and 23 andan additional gas station 24. At each vacuum station, each chambercommunicates with a vacuum source 33 which evacuates the air from thechamber to exhaust the oxygen from the pouch 16. At each gas station,each chamber communicates with a source 34 of non-oxidizing gas such asnitrogen which is introduced into the pouch to drive out any trappedoxygen. As a result of the multiple purgings, the. oxygen content of thepouch is reduced to a very low level.

After leaving the gas station 24, each chamber 27 is advanced to aclosing or sealing station 35 (FIGS. 2, 12 and 13). As the turret dwellsat the sealing station, the holder 29 is raised out of the chamber toplace the pouch 16 in an overlying enclosure 36 where the top of thepouch is sealed, the enclosure being filled with nitrogen so as toprevent oxygen from entering the pouch when it is raised from thechamber for sealing. The sealing is effected by a pair of opposed heatedseal bars 3611 which are'disposed within the enclosure and which areadapted to be reciprocated by conventional airoperated mechanismindicated generally at 3612. When sealed, the pouch appears generally asindicated in FIG. 14.

After being sealed, the pouch 16 is lowered out of the enclosure 36 andback into the chamber 27 and is indexed two steps to a station 37 (FIG.2). The holder 29 then is raised out of the chamber once again andfinally is indexed one additional step to an unloading station 39 wherethe pouch is automatically removed from the raised holder. On the nextindex, the holder is advanced to the loading station to receive anotherpouch from the packager 17.

The turret 25 is supported rigidly on the upper end ofa vertical shaft40 (FIGS. 3 and 10) which is adapted to be rotated intermittently by aright angle index drive 41 (FIGS. 1 and 3) mounted on the machinesupport or frame whose various elements have been indicated collectivelyby the reference numeral 43. An input shaft 44 (FIG. 1) is connected tothe index drive 41 and is rotated continuously by chain drive 45connected to the power-driven cycle shaft 46 of the packager l7.'

Each of the shells 26 of the'turret 25 is box-like in shape and slidablyreceives an upright rod 47 (FIG. 3) whose upper end carries the pouchholder 29. When the shell 26 is indexed one step past theloading'station 30 and into the lowering station 31, a pair of flanges49 (FIG. 8) on the lower end of the rod move into straddlingrelationship with a lug 50 carried on a vertically movable chain 51. Asthe'shell dwells, the chain drives the lug 50 downwardly to shift therod 47 downwardly and thus move the raised holder 29 downwardly into thechamber 27 defined by the shell 26 (see the position shown in phantom inFIG. 8). After the turret 25 indexes, the chain 51 returns the lug 50 toits original position to await the rod 47 of the next shell. A similarchain 53 and lug 54 (FIG. 10) are located at the raising station 37adjacent the unloading station 39 but are driven in a direction to shifteach holder 29 upwardly out of its respective shell 26 when the latterdwells at the raising station. The chains 51 and 53 are connected to aright angle gear box 55 which, in turn, is driven intermittently by aparallel index drive 56 (FIGS. 1 and 2) whose input shaft 57 isconnected to the turret input shaft 44 by a chain 59.

Just after each holder 29 moves past the lowering lug 50, the flanges 49on its rod 47 ride onto a rail 59a (FIGS. 3, 10 and 11) which supportsthe holders vertically when the latter are in their lowered positions. Avertically spaced rail 5912 supports the holders in their raisedpositions from the time the holders leave the lifting lug 54 until thetime they are picked up by the lowering lug 50.

To first raise and then lower each holder 29 when the latter is in thesealing station 35, a vertically reciprocable'slide 60 FIG'. 11') issuppor'ted beneath the sealing station and carries'a lug '61 w hich'the' flanges 49 on each rod 47 straddle as the rod moves into thesealing station. When the rod dwells, the slide 60 shifts first upwardlyand then "downwardly toraise and lower the holder. The slideisreciprocated by acam 63 which is rotated by the'stub end 64 of theturret input shaft 44 and which is connected to the slide by a followerand lever mechanism indicated generally by the reference numeral'65.

Each pouch holder 29 comprises an oblong body 66 (FIGS. 5 to 7)fabricated from plastic and oriented with its long horizontal axisextending along a radius of the turret 25. A compartment 67 forreceiving the pouch 16 is defined within the body and opens bothoutwardly and upwardly. At the loading station 30, each pouch isdelivered edgewise and radially into the compartment with the lower endof the pouchbeing received in and guided by a narrow slot 69 (FIG. 5)formed in the body at the lower end of the compartment. Two wires 70 arelocated on opposite sides of the compartment adjacent the upper endthereof and gradually taper toward one another as they progress towardthe inner end of the compartment. The wires help guide the pouch into apouch clamp 71 having a fixed jaw 73 and a movable jaw 74, the latterbeing carried on a torsion rod 75 (FIG. 7) which urges the movable jawtoward the fixed jaw. When the holder first dwells at the loadingstation 30, an air-actuated cylinder76 (FIG. 2) on the frame 43 moves anL-shaped operating mq ber 77 into engagement with an ear 79 (FIG. 5) onthe movable jaw so as to wind up the torsion rod, open the clamp 71 andpermit the pouch to move between the jaws. Thereaf- I ter, the cylinderretracts the operating member to cause the jaw 74 to close and grip thepouch within the holder. A similar cylinder 80 and operating member 81(FIG. 2) are located adjacent the u nloading station 39 and serve toopen each clamp dwelling that station so that the pouch may be removedfrom the holder.

To deliver the pouches 16 into the holders 29 at the loading station 30,an intermittently movable conveyor chain 83 (FIG. 1') is disposed in avertical plane adjacent the loading station and extends to thedownstream end of the packager 17. The conveyor chain carries spacedclamps 84 each adapted to pick' up a pouch coming off of the packagerand then to carry the pouch into the holder for gripping by the clamp 71(see FIG. 3). Suitable means (not shown) are provided for opening theclamps 84, first at the packager 17 to receive the pouches and then atthe loading station 30 to release the pouches. A similar conveyor chain85 (FIG. 1) with clamps 86 extends outwardly from the unloading station39 and'serves to pick up the pouches from the holders in the unloadingstation and to carry such pouches outwardly away from the turret 25 forfurther handling.

One of the important features of the invention is that the chambers 27are tightly sealed as they advance between the purg'ing stations 19 to24 and that communication between the chambers and the vacuum and gassources 33 and 34 is established without the need of complex valving.These ends are achieved through the provision of a stationary member orplate 87 (FIGS. 1 and 3) which is rigidly secured to the frame 43 andwhich overlies'the top'of the turret 25. The underside of the plate 87is precisely flat and horizontal and mates intimately with a highdensity polyethylene seal gasket 89 (FIG. 3) anchored to the upper sideof the turret, the gasket being formed with openings which overlie andregister with the chambers 27. Thus, the plate and the gasket coact toisolate the chambers from one another and to prevent the outsideatmosphere from entering the chambers as the latter advance between thefirst vacuum station 19 and the sealing station 35. Holes 90 are formedthrough the plate at the sealing station 35 and between the raising-andlowering stations 37 and 31 in order to enable the holders to move intoand out of the chambers 27.

To evacuate the chambers 27, the vacuumsource 33 is connected to severallines 91 (FIGS. 2 and 3) which extend through the plate 87'at the vacuumstations 19,

20, 22 and 23 and communicate with the chambers as the chambers moveinto those stations. In a similar manner, the gas source 34 is connectedto lines 93 (FIG. 2) extending through the plate 87 at the gas stations21 and 24 and is further connected to an additional line 94 (FIG. 13)leading to the enclosure 36 at the sealing station 35. The vacuum andgas sources are operated continuously and, since the chambers 27 movearound to the different stations 19 to 24 and the station 35, there isno need to provide shut-off valves in the individual lines 91, 93 and94.

To summarize briefly, each pouch 16 discharged by the packager 17 ispicked up by the conveyor chain 83 and is placed in the raised holder 29at the loading station 30 After the turret has been indexed through onestep to the station 31, the holder and the gripped pouch are lowered bythe chain 51 to retract the holder downwardly into the chamber 27 andbeneath the plate 87. The pouch then is indexed through the purgingstations 19 to 24 where virtually all of the oxygen in the pouch isremoved by virtue of the evacuating and gassing. After reaching thesealing station 35, the holder29 is raised upwardly into the enclosure36 by the cam 63 so that the pouch may besealed by the bars 36a in thepresence of the non-oxidizing gas in the enclosure. The cam then lowersthe holder back into the chamber 27 and, after the holder has beenindexed two steps to the station 37, the chain 53 shifts the holder toits raised position preparatory to the holder being indexed totheunloading station 39 for removal of the pouch, by the conveyor chain 85.

I claim as my invention;

1. A machine for establishing a non-oxidizing atmosphere withinopen-ended packages and for closing the open ends of the packages, saidmachine comprising a support, an indexable turret rotatable step-by-stepabout a predetermined axis on said support and having a series ofopen-ended chambers spaced angularly around said axis, each of saidchambers stopping at angularly spaced loading, conditioning and closingstations when said turret dwells between steps, a package holderassociated with each chamber and movable between an extended positionlocated out of the chamber and a retracted position disposed in thechamber, each of said holders being in its extended position when theassociated chamber is in said loading station whereby a package may beloaded into the holder, means for retracting each loaded holder into itsrespective chamber prior to advancement of the chamber into theconditioning station, a stationary member located in said conditioningstation and sealing off the open end of each chamber in the conditioningstation, means communicating with each chamber in the conditioningstation for establishing a non-oxidizing atmosphere within the packagein such chamber, means for extending each holder from .itsrespectivechamber after such chamber advances into said closing station, and meansin said closing station for sealing the open end of the package in eachextended holder in the closing station thereby to maintain thenon-oxidizing atmosphere within the package.

2. A machine for establishing a non-oxidizing atmosphere withinopen-topped packages and for closing the tops of the packages, saidmachine comprising a support, an indexable turret' rotatablestep-by-step about an upright axis on said support and having a seriesofupwardly opening chambers spaced angularly around said axis, each ofsaid chambers stopping at angularly spaced loading, conditioning andclosing sta tions when said turret dwells between steps, a packageholder associated with each chamber and movable between a raisedposition located out of the chamber and a lowered position disposed inthe chamber, each of said holders being in its raised positionwhen theassociated chamber is in said loading station whereby a package may beloaded into the holder, means for lowering in the conditioning station,means communicating with each chamber in the conditioning station forestablis hing a non-oxidizing atmosphere within the package in suchchamber, means for raising each holder" from its respective chamberafter such chamber advances "into said closing station, and means insaid closing station for sealing the top of thepackage in each raisedholder' in the closing station thereby to maintain the nonoxidizingatmosphere withinthe package.

3. A machine defined in claim 2 in which there are a plurality ofangularly spaced conditioning stations located between said loadingstation and said closing sta tion, and means communicating with eachchamber in' each conditioning station for establishing the ,non-

oxidizing atmosphere within the package such chamber.

4. A machine as defined in claim 3 in which said lastmentioned meansinclude means in at least one condiv tioning station for evacuating theatmosphere from each chamber in such station and further including meansin at least one other conditioning station for injecting thenon-oxidizing, gas into each chamber in such station.

5. A machine as defined in claim 4 in which said stationary member sealsoff the upper ends of all of said chambers in said conditioning stationsand keeps said chambers sealed off as they advance between saidconditioning stations.

6. A machine as defined in claim 5 in which said stationary membercomprises a plate overlying said turret, said evacuating means and saidinjecting means communicating with said chamber through said plate whensaid chambers dwell in the associated conditioning stations, and meansfor establishing a substantially gastight seal between the upper side ofsaid turret and the lower side of said plate while permitting saidturret to rotate relative to said plate.

7. A machine as defined in claim 2 in which said closing means compriseopposed sealing bars located in said sealing station above said turret,an enclosure surrounding said sealing bars, and means for establishingthe non-oxidizing atmosphere within said enclosure.

8. A machine as defined in claim 7 in which said means for raising saidholders in said closing station are operable first to raise said holderinto said enclosure and then to lower said holder back into theassociated chamber after the top of the package has been sealed by saidbars and before the chamber is advanced out of said closing station.

9. A machine as defined in claim 2 further including an unloadingstation located between said closing station and said loading station,and means for raising each holder out of its chamber after the chamberhas been advanced out of said closing station whereby the package insaid holder may be removed therefrom at said unloading station.

10. A machine defined in claim 2 further including means forautomatically loading a package into each raised holder in said loadingstation and for automatically removing the package from each raisedholder in said unloading station.

11. A machine for establishing a non-oxidizing atmosphere in open-toppedpouches and for closing the tops of the pouches, said machine comprisinga support, an indexable turret rotatable step-by-step about an uprightaxis on said support and having a series of upwardly opening chambersspaced angularly about said'axis, each of said chambers stopping atangularly spaced loading, first conditioning,'second conditioning,closing and unloading stations when said turret dwells between steps, apouch holder associated with each chamber and movable between a raisedposition located out of the chamber and a lowered position disposed inthe chamber. each of said holders being in a raised position when theassociated chamber is in said loading station, means in said loadingstation for automatically loading a pouch into each raised holder in theloading station, means for lowering each loaded holder into itsrespective chamber prior to advancement of the chamber into the firstconditioning station, a stationary member overlying said turret andclosing off the upper ends of said chambers from the time the chambersare moved to first conditioning station until just prior to the time thechambers reach said sealing station, means in one of said conditioningstations and communicating through said stationary member with eachchamber in such station to evacuate the atmosphere from such chamber,means in the other of said conditioning stations and communicatingthrough said stationary member with each chamber in such station tointroduce a non-oxidizing gas into such chamber, opposed sealing barslocated in said sealing station above said turret, an enclosuresurrounding said sealing bars, means for establishing a non-oxidizingatmosphere within said enclosure, means for raising each holder in saidsealing station out of its chamber to place the pouch in said holderinto said enclosure, said last-mentioned means being operable to lowerthe raised holder back into the associated chamber after the top of thepouch has been sealed by said bars and before the chamber is advancedout of said sealing station, means for raising each holder out of itschamber after the chamber has been advanced out of said sealing station,and means in said unloading station for automatically removing the pouchfrom each raised holder in said unloading station. I

12. A machine as defined in claim 11 further including at least twoadditional conditioning stations located between said first conditioningstation and said sealing station, means in one of said additionalstations and communicating through said stationary member with eachchamber in such station to evacuate the atmosphere from such chamber,and means in the other of said additional stations and communicatingthrough said stationary member with each chamber in such station tointroduce a non-oxidizing gas into such chamber.

13. A machine as defined in claim 11 further including at least fouradditional conditioning stations located between said first conditioningstation and said sealing station, means in at least one of saidadditional stations and communicating through said stationary memberwith each chamber in such station to introduce a nonoxidizing gas intosuch chamber, and means in the other additional stations andcommunicating through said member with the chambers in such stations toevacuate the atmosphere in such chambers.

14. A machine as defined in claim 13 in which said conditioning stationsare spaced around said axis such that each chamber advances first intotwo evacuating stations, then into a gas introducing station, then intotwo more evacuating stations and then into another gas introducingstation.

15. A machine as defined in claim 11 in which said stationary membercomprises a plate overlying said turret, and means for establishing asubstantially gas-tight seal between the upper side of said turret andthe lower side of said plate while permitting said turret to rotaterelative to said plate.

1. A machine for establishing a non-oxidizing atmosphere withinopen-ended packages and for closing the open ends of the packages, saidmachine comprising a support, an indexable turret rotatable step-by-stepabout a predetermined axis on said support and having a series ofopen-ended chambers spaced angularly around said axis, each of saidchambers stopping at angularly spaced loading, conditioning and closingstations when said turret dwells between steps, a package holderassociated with each chamber and movable between an extended positionlocated out of the chamber and a retracted position disposed in thechamber, each of said holders being in its extended position when theassociated chamber is in said loading station whereby a package may beloaded into the holder, means for retracting each loaded holder into itsrespective chamber prior to advancement of the chamber into theconditioning station, a stationary member located in said conditioningstation and sealing off the open end of each chamber in the conditioningstation, means communicating with each chamber in the conditioningstation for establishing a non-oxidizing atmosphere within the packagein such chamber, means for extending each holder from its respectivechamber after such chamber advances into said closing station, and meansin said closing station for sealing the open end of the package in eachextended holder in the closing station thereby to maintain thenon-oxidizing atmosphere within the package.
 2. A machine forestablishing a non-oxidizing atmosphere within open-topped packages andfor closing the tops of the packages, said machine comprising a support,an indexable turret rotatable step-by-step about an upright axis on saidsupport and having a series of upwardly opening chambers spacedangularly around said axis, each of said chambers stopping at angularlyspaced loading, conditioning and closing stations when said turretdwells between steps, a package holder associated with each chamber andmovable between a raised position located out of the chamber and alowered position disposed in the chamber, each of said holders being inits raised position when the associated chamber is in said loadingstation whereby a package may be loaded into the holder, means forlowering each loaded holder into its respective chamber prior toadvancement of the chamber into the conditioning station, a stationarymember located in said conditioning station and sealing off the upperend of each chamber in the conditioning station, means communicatingwith each chamber in the conditioning station for establishing anon-oxidizing atmosphere within the package in such chamber, means forraising each holder from its respective chamber after such chamberadvances into said closing station, and means in said closing stationfor sealing the top of the package in each raised holder in the closingstation thereby to maintain the non-oxidizing atmosphere within thepackage.
 3. A machine as defined in claim 2 in which there are aplurality of angularly spaced conditioning stations located between saidloading station and said closing station, and means communicating witheach chamber in each conditioning station for establishing thenon-oxidizing atmosphere within the package in such chamber.
 4. Amachine as defined in claim 3 in which said last-mentioned means includemeans in at least one conditioning station for evacuating the atmospherefrom each chamber in such station and further including means in atleast one other conditioning station for injecting the non-oxidizing gasinto each chamber in such station.
 5. A machine as defined in claim 4 inwhich said stationary member seals off the upper ends of all of saidchambers in said conditioning stations and keeps said chambers sealedoff as they advance between said conditioning stations.
 6. A machine asdefined in claim 5 in which said stationary member comprises a plateoverlying said turret, said evacuating means and said injecting meanscommunicating with said chamber through said plate when said chambersdwell in the associated conditioning stations, and means forestablishing a substantially gas-tight seal between the upper side ofsaid turret and the lower side of said plate while permitting saidturret to rotate relative to said plate.
 7. A machine as defined inclaim 2 in which said closing means comprise opposed sealing barslocated in said sealing station above said turret, an enclosuresurrounding said sealing bars, and means for establishing thenon-oxidizing atmosphere within said enclosure.
 8. A machine as definedin claim 7 in which said means for raising said holders in said closingstation are operable first to raise said holder into said enclosure andthen to lower said holder back into the associated chamber after the topof the package has been sealed by said bars and before the chamber isadvanced out of said closing station.
 9. A machine as defined in claim 2further including an unloading station located between said closingstation and said loading station, and means for raising each holder outof its chamber after the chamber has been advanced out of said closingstation whereby the package in said holder may be removed therefrom atsaid unloading station.
 10. A machine as defined in claim 2 furtherincluding means for automatically loading a package into each raisedholder in said loading station and for automatically removing thepackage from each raised holder in said unloading station.
 11. A machinefor establishing a non-oxidizing atmosphere in open-topped pouches andfor closing the tops of the pouches, said machine comprising a support,an indexable turret rotatable stepby-step about an upright axis on saidsupport and having a series of upwardly opening chambers spacedangularly about said axis, each of said chambers stopping at angularlyspaced loading, first conditioning, second conditioning, closing andunloading stations when said turret dwells between steps, a pouch holderassociated with each chamber and movable between a raised positionlocated out of the chamber and a lowered position disposed in thechamber, each of said holders being in a raised position when theassociated chamber is in said loading station, means in said loadingstation for automatically loading a pouch into each raised holder in theloading station, means for lowering each loaded holder into itsrespective chamber prior to advancement of the chamber into the firstconditioning station, a stationary member overlying said turret andclosing off the upper ends of said chambers from the time the chambersare moved to first conditioning station until just prior to the time thechambers reach said sealing station, means in one of said conditioningstations and communicating through said stationary member with eachchamber in such station to evacuate the atmosphere from such chamber,means in the other of said conditioning stations and communicatingthrough said stationary member with each chamber in such station tointroduce a non-oxidizing gas into such chamber, opposed sealing barslocated in said sealing station above said turret, an eNclosuresurrounding said sealing bars, means for establishing a non-oxidizingatmosphere within said enclosure, means for raising each holder in saidsealing station out of its chamber to place the pouch in said holderinto said enclosure, said last-mentioned means being operable to lowerthe raised holder back into the associated chamber after the top of thepouch has been sealed by said bars and before the chamber is advancedout of said sealing station, means for raising each holder out of itschamber after the chamber has been advanced out of said sealing station,and means in said unloading station for automatically removing the pouchfrom each raised holder in said unloading station.
 12. A machine asdefined in claim 11 further including at least two additionalconditioning stations located between said first conditioning stationand said sealing station, means in one of said additional stations andcommunicating through said stationary member with each chamber in suchstation to evacuate the atmosphere from such chamber, and means in theother of said additional stations and communicating through saidstationary member with each chamber in such station to introduce anon-oxidizing gas into such chamber.
 13. A machine as defined in claim11 further including at least four additional conditioning stationslocated between said first conditioning station and said sealingstation, means in at least one of said additional stations andcommunicating through said stationary member with each chamber in suchstation to introduce a non-oxidizing gas into such chamber, and means inthe other additional stations and communicating through said member withthe chambers in such stations to evacuate the atmosphere in suchchambers.
 14. A machine as defined in claim 13 in which saidconditioning stations are spaced around said axis such that each chamberadvances first into two evacuating stations, then into a gas introducingstation, then into two more evacuating stations and then into anothergas introducing station.
 15. A machine as defined in claim 11 in whichsaid stationary member comprises a plate overlying said turret, andmeans for establishing a substantially gas-tight seal between the upperside of said turret and the lower side of said plate while permittingsaid turret to rotate relative to said plate.